1. Field
The present invention involves a non-imaging target sensor with a single silicon detector element responsive to the visible and more particularly to the near infrared light spectrum. This detector being structured to have a very narrow angle of view. The problem addressed is the substitution of this sensor for an ordinary camera in a high vibration environment.
2. Prior Art
In the U.S. Army's attack helicopter there is an ordinary movie camera mounted in a special support structure. This support structure moves with the helicopter's gun mounts to keep the camera boresighted with the guns. The resulting films are later used to assess the skill of the operator and the effectiveness of the gun sighting mechanism. In warfare it is also used to make damage assessments of specific targets and thereby to aid in strategic decisions. A future aim is to use such recorded information to design automatic target recognition devices and associated systems.
It is proposed that the above detector be mounted in place of the movie camera to obtain certain data which is presently classified and was not needed, nor available to this applicant. This exchange is feasible since the cameras are designed for easy removal from their limited access mounting niches in order to facilitate film loading and unloading. To accomplish this the bottom rear surface of the camera carries a rearward projecting foot structure with a vertical pin that extends downward to engage the camera support structure. Also the front surface of the camera includes a projecting ring structure that surrounds the camera aperture. The ring structure contains an outer circumferential groove that carries an O-ring. The ring fits into a matched opening in the support structure which also has a groove to receive the O-ring in a snap fit. The support structure carries the camera lens in coaxial relation to the matched opening, so that the lens elements, filters, etc. remain in place as the camera is removed. A clamping device on the support structure engages the top of the foot structure to complete the assembly of the camera and support.
Due to the narrow angle of view associated with the detector, this element needs a special mounting means for achieving a very accurate alignment between the optical axis of the detector and the optical axis of the more firmly mounted lens. The mounting means must also be compatible with the camera mounting in the aircraft. If an adjustable system is used, it must be capable of withstanding tremendous vibration stresses and be adapted to provide very small angular adjustments in azimuth, elevation and translation along the optical axis. The controls for these adjustments must also be readily accessible in the cramped environment alloted in the aircraft. The mounting means also includes an electrical coupling wired to the detector so that these elements together form a sensor module. A cable is run from the sensor to the supporting electronics or signal processor which can be placed at any convenient location in the gunship or helicopter. Intelligent signal processors are used to wring out and record every possible detail from the sensors output.
An object of the present invention is, therefore, to provide a replacement sensor module for the camera, which can be quickly emplaced and accurately aligned with the optical axis of the camera support and will maintain this condition under extreme vibration.